Events leading to the destruction of articular cartilage from infection are being investigated. Common clinical isolates of bacteria were investigated for their ability to excrete collagenase and the same studies will be carried out with regard to enzymes which may degrade proteoglycan. Techniques to measure antibiotic penetration into synovial fluid have been developed and the ability of variety and commonly used antibiotics in clinical practice have been investigated for their ability to enter joints which are normal or infected. A new model of noninfectious inflammatory arthritis involving the direct inoculation of Mycobacterium butyricum in mineral oil directly into the joint is being investigated. A new method of analyzing glycosaminoglycan content of articular cartilage is being perfected and will be used to correlate this cartilage constituent with disease activity and cartilage constituent with disease activity and cartilage destruction. Rat adjuvant arthritis successfully responds to joint irradiation, total lymphoid irradiation or the combination of both therapies. This work is being pursued as a rationale for use as a treatment vehicle in patients with intractable rheumatoid arthritis.